It is well known to provide an internal combustion engine with a turbocharger to enhance engine performance. The basic components of a turbocharger are a gas turbine driven by engine exhaust and a compressor powered by the turbine for compressing and directing atmospheric air under pressure to engine air intake. U.S. Pat. Nos. 2,780,053, 3,498,053, and 3,734,074 teach various turbochargers. Prior art also discloses the use of a cross turbocharger, i.e. a system in which a left turbocharger connected to a left bank of cylinders charges a right bank of cylinders and a right turbocharger connected to a right bank of cylinders charges a left bank of cylinders. For example, U.S. Pat. No. 3,027,706 teaches a cross-over system.
In any turbocharger, crossed or not, the piping used to connect the various parts of the turbocharger and to connect the turbocharger with the rest of the engine is complex. This complex design causes adverse consequences such as increased engine size, more severe and frequent maintenance problems, and decreased efficiency. The decreased efficiency results from phenomena such as gas friction.
Because the turbocharger relies on the engine exhaust to power the turbine, the turbocharger provides little or no charge when the engine is first started. In fact, the stopped compressor impedes intake of air and actually makes starting more difficult. Start-up difficulties with turbochargers are particularly a problem with diesel engines.
As this discussion illustrates, there is a need for an improved system for cross turbocharging.